Department of Veterinary Clinical Sciences, Small Animal Clinic-Surgery, Justus-Liebig-University, Giessen, Germany.
Institute of Zoology and Evolutionary Research, Friedrich-Schiller-University, Jena, Germany.
PLoS One. 2023 Jan 17;18(1):e0278665. doi: 10.1371/journal.pone.0278665. eCollection 2023.
Our knowledge about the underlying pathomechanisms of craniocervical junction abnormalities (CCJA) in dogs mostly derives from measurements based on tomographic imaging. These images are static and the positioning of the dogs' head does not reflect the physiological in vivo position of the craniocervical junction (CCJ). Aberrant motion patterns and ranges of motion (ROM) in sound individuals of CCJA predisposed breeds may be a pathogenetic trigger. To further extend our limited knowledge of physiological motion of the CCJ, this prospective, comparative study investigates the in vivo motion patterns and ROM of the CCJ in walk and trot in sound Cavalier King Charles Spaniels and Chihuahuas. The Labrador retriever is used as a reference breed without predisposition for CCJA. This is the first detailed description of CCJ movement of trotting dogs. Biplanar fluoroscopy images, recorded in walking and trotting dogs, were matched to a virtual reconstruction of the skull and cranial cervical spine utilising Scientific Rotoscoping. Kinematic data reveal the same motion patterns among all breeds and gaits with individual temporal and spatial differences in each dog. A stride cycle-dependent lateral rotation of the cranial cervical spine and axial rotation of the atlantoaxial joint in trot in dogs is described for the first time. The ROM of the atlantoaxial and atlantooccipital joints in walk and trot were not statistically significantly greater in the CCJA-predisposed breeds CKCS and Chihuahua. ROM values of all translational and rotational degrees of freedom were larger in walk than trot, although this is only statistically significant for the atlantoaxial joint. Until proven otherwise, a more species-specific than breed-specific general motion pattern of the CCJ in walking and trotting, clinically sound dogs must be assumed. Species-specific anatomic properties of the CCJ seem to supersede breed-specific anatomical differences in clinically sound dogs.
我们对犬颅颈交界异常（CCJA）潜在病理机制的了解主要来自于基于断层成像的测量。这些图像是静态的，狗的头部位置并不能反映颅颈交界（CCJ）的生理体内位置。在 CCJA 易感性品种的健康个体中，异常的运动模式和运动范围（ROM）可能是致病的触发因素。为了进一步扩展我们对 CCJ 生理运动的有限认识，这项前瞻性、比较研究调查了健康的骑士查理王小猎犬和吉娃娃在行走和小跑时 CCJ 的体内运动模式和 ROM。拉布拉多猎犬被用作没有 CCJA 易感性的参考品种。这是首次详细描述小跑犬的 CCJ 运动。在行走和小跑的狗中记录的双平面荧光透视图像，利用科学旋转技术与颅骨和颅颈脊柱的虚拟重建相匹配。运动学数据显示，所有品种和步态的运动模式相同，每只狗的个体时间和空间差异。首次描述了狗小跑时颅颈交界处的侧向旋转和寰枢关节的轴向旋转与步幅周期有关。在行走和小跑时，CCJA 易感性品种 CKCS 和吉娃娃的寰枢关节和寰枕关节的 ROM 没有统计学上的显著差异。行走和小跑时所有平移和旋转自由度的 ROM 均大于行走时，尽管这仅在寰枢关节时具有统计学意义。在有其他证据之前，必须假设在行走和小跑时，健康犬的 CCJ 具有比品种特异性更具物种特异性的一般运动模式。CCJ 的物种特异性解剖特性似乎超过了健康犬的品种特异性解剖差异。
